The present invention relates to a supporting and adjusting device for countercutter rails of field choppers having a cutting element with a partially surrounding bottom, and a saddle which supports the countercutter rail and has an adjustable distance to the outer surface of the cutting element.
A supporting and adjusting device of the above mentioned general type is known in the art. In the field choppers of this type the countercutter rail must be mounted on a support in a non-displaceable manner during the operation to take up significant cutting forces, and at the same time must be simply actuatable from outside to adjust the countercutter rail.
German documents DE-PS 2,926,538 and DE-OS 3,302,861 disclose two different approaches to solve this problem. In both cases the field chopper has a cutter drum supported in a box with the side walls and a support fixedly mounted between the side walls for the countercutter rail supported thereon. They are fixed at their both ends and outside the side walls, and tensioned to a certain degree. The value of tensioning is limited by the fact that the countercutter rail must be displaceable for the adjustment. These approaches have the disadvantage in that the countercutter rail must be designed so as to withstand high forces so that it can take up spreading forces occurring during cutting without significant lasting deflection. Another difficulty is that the countercutter rail which loosely lies in the region of the cutter drum and is pretensioned only outwardly has a tendency to vibration under the action of the periodically acting cutting forces. This results in disadvantages for the holding strength and the cutting accuracy.